Mascara brush



FIG. 1 is a perspective view of mascara brush showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a reduced perspective view thereof, the broken lines being included to illustrate environmental structure which forms no part of the claimed design. 

The ornamental design for a “mascara brush,” as shown and described. 